Rainforests: A Great Mysterious World

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Updated on: Educator Review By: Michelle Connolly

Rainforests are ecosystems in the equatorial circle between latitudes 10 degrees north and south of the equator. This habitat is known for its extreme annual rainfall and high average temperatures. Tropical forests found in Asia, Central America, Mexico, Australia, Africa, South America, and several islands of the Pacific, the Caribbean, and the Indian Ocean are within the classifications of biotopes.

For the World Wildlife Fund, the tropical rainforest is believed to be a type of substantial tropical forest with a tree diameter of about 50 meters. This case occurs in the Congo River basin in Central Africa and the Amazon River basin in South America. At the same time, the size and density of these forests vary in Southeast Asia, the Caribbean basin, and others.

The climate of the tropical rainforest can be described in two words: hot and humid, with average annual precipitation that is not less than 168 cm and may exceed 1,000 cm. This extreme level of rain often affects poor soils due to the leaching of soluble nutrients.

In areas with high biodiversity, between 40% and 75% of all biological species are found to be rainforest-specific. Half of all plant and animal species on the world call them home. Surprisingly, rainforests are home to two-thirds of all flowering plants. One hectare may contain the rainforest contains 42,000 species of various insects, for example, “reptiles, snakes, and the tsetse fly that causes sleeping sickness,” and around 807 tree species “rubber, date palm, and mahogany,” and 1,500 other species of different plants.

Due to the fact that they are home to more than a quarter of all known natural medicines, tropical rainforests are referred to as the largest pharmacy in the world. In tropical rainforests, there are probably millions of species of undiscovered plants, animals, and microbes.

Due to extensive fragmentation and human activity, rainforests are among the most endangered ecosystems on the planet. In addition, habitat fragmentation brought on by geological phenomena like volcanism and climate change has happened. Yet, habitat loss is one of the main reasons for extinction, along with most humans. The 20th century saw extensive agricultural clearing and substantial logging in tropical rainforests. Unfortunately, the world’s rainforests are rapidly losing land.

Historical Background:

Hundreds of millions of years ago, there were tropical rainforests on Earth, and most tropical rainforests are today in parts of the giant Mesozoic era of Gondwana. Rainforests can be divided into the following regions of the world:

  1. America.
  2. Africa.
  3. Southeast Asia.
  4. Madagascar.
  5. New Guinea and small regions of Australia.

However, due to the poor fossil record, information regarding the origin of the rainforest are still unknown.

Rainforest Types

Many of us are fascinated by the colour green, which inspires life. Whenever we look at a green land, goodness, energy, and prosperity, come to our minds. You will find these green spots worldwide, especially in the rainforests.

Rainforests cover approximately 6% of the Earth’s surface area, contain tall and dense trees and plants in which large numbers of different animals live, and can be described as jungles. The annual precipitation rate rises in rainforests characterised by a scorching climate and wet imposed on animals and plants the need to adapt and adapt to these conditions. There are several types of tropical rainforest for the general biome, including:

Tropical lowlands: are evergreen rainforests, which are defined as forests that consistently get heavy precipitation “of more than 2,000 mm, or 80 inches yearly.” The majority of these forests, which are in the Amazon and Congo Basins, are found in the region surrounding the equator. Indonesia and New Guinea are both in Central Africa.

Semi-evergreen forests: seasonal moist forests with heavy rainfalls during the hot, humid summer season and the dry season to come in the cold winter season, and some trees in these forests may shed some leaves during the dry season in winter, and these forests are found in some regions of South and Central America, the Caribbean, Indochina, in coastal West Africa, parts of the Indian subcontinent.

Mountain rainforests: some of them are situated in mountainous areas with cooler conditions and are referred to as cloud forests. Mountain rainforests often have a top limit of 2,400-3,300 m and a lower limit between 1,500 and 2,500 m, depending on latitude. In the waters of the Amazon basin and Peru, seven different types of submerged woods exist:

  1. The bog is permanently waterlogged over the former oxbow’s forests and lakes and is still covered by forest.
  2. There is a seasonal inundation of lakes and swamp forests oxbow.
  3. There are fewer forests in the floodplains of Chambi Forest.
  4. Tall forests, central floodplains, and some neighbourhoods were flooded.
  5. Tall forests, and upper floodplains, rarely flooded.

Rainforest Features

Rainforests are the most biologically diverse terrestrial ecosystem. They form a biome that manifests in the form of large clumps of vegetation in the intertropical strip.

Plant structure

The tropical forest presents a complex vegetation structure consisting of 4 to 5 layers of vegetation and varying degrees of epiphytes and climbers (plants climbing on other plants). In the case of a semi-humid tropical forest, the structure is more straightforward, with only two or three layers.

Leaves and light

The different adaptations of plants in tropical forests are conditioned by light, soil depth, or high relative humidity. Solar radiation enters the woods in a vertical gradient that affects leaf size and structure. Sunlight is intense in the canopy, and leaves tend to be small.

In the middle layers, the leaves have a broader and thinner lamina and tend to be more significant in the lower plants. This way, it is possible to take advantage of the faint light radiance that manages to penetrate the forest.

Tabular or lateral roots

In many rainforests, the soil is shallow, and large trees cannot develop deep roots, which limits their ability to support. That is why they develop extensive lateral roots resembling the buttresses of medieval churches.

High relative humidity

The relative humidity is very high in tropical rainforests with high temperatures and heavy rains. Plants sweat (release water vapour) through the stomata in the leaves.

When the relative humidity in the environment is very high, as in many tropical forests, transpiration becomes difficult. For this reason, some plant species have developed an active mechanism for releasing water in liquid form. This process is known as tearing and is conducted through pores called hydras located at the margins of the leaf.

Soil nutrient cycle

In general, the soils of tropical forests could be more fertile and, in some cases, shallow. In tropical forests, nutrients accumulate in plant biomass and the litter on the soil surface. The cycle of nutrients in an ecosystem is associated with decomposers and the mycorrhizal network.


Most areas where tropical forests develop have a common biogeographic history. The entire region corresponding to South America, Africa, Madagascar, India and Australia was part of the ancient continent of Gondwana 200 million years ago.

This continent separated from the Jurassic and Cretaceous periods to the present day. Many plants and animals in these tropical forests have relationships, mainly at the family level.

Rainforest role in Planetary Balance

Carbon leakage

Rainforests are the most productive terrestrial ecosystem on the planet, and their ability to accumulate biomass makes them an important carbon sink. Therefore, every tree in the forest incorporates carbon dioxide into the atmosphere and fixes the carbon as plant tissues.

This condition contributes to regulating carbon dioxide in the atmosphere and reducing global warming, which today is one of the biggest environmental threats.

Oxygen production

Rainforests are not lungs (they do not consume oxygen and do not emit carbon dioxide). They perform the opposite function. Rainforests take in carbon dioxide and release oxygen into the environment, but they also take in oxygen when they breathe. These ecosystems are one of the significant sources of oxygen, overtaken by marine phytoplankton.

Water Cycle

Tropical rainforests are enormous clumps of plants that percolate, take water from the ground, filter it and expel it into the environment as vapour. On the other hand, the forest acts as a great soil protector, slowing water run-off and facilitating infiltration.

Rainforest Structure

The rainforest is separated into levels, and each layer is defined as a distinct biological community that contains numerous animals and plants that have adapted to living in those layers by plants growing vertically from the top of the earth. While other layers can also be found in the temperate rainforest, the emerging layer is specific to the tropical rainforest.

Rainforest Floor

The forest floor and most of the lower layers usually receive as low as 2% of the sun’s rays, and the plants that grow in it adapt to the dim lighting and away from the banks of rivers, swamps and trees; dense shrubs are also found in the forests. The area with the most extensive freedom of movement for giant creatures, including ungulates like the okapi, tapir, and Sumatran rhinoceros.

Together with gorillas from the western plains, numerous species of insects, amphibians, and reptiles exist. The warm, humid weather promotes rapid decay, thus, the forest floor is also home to decaying plants and animals that vanish quickly. Several fungus flourish to aid in the decomposition of animal and plant waste.

Canopy layer

The basic layer of a forest’s two uppermost layers, which are covered in enormous trees that are typically 30 to 45 metres tall, is called the canopy. Epiphytes, which include orchids, mosses, and lichens, have abundant support. For the purpose of obtaining water and nutrients from rain and silt that accumulates on the supporting plants, these epiphytes adhere to the trunks and branches of trees.

Emerging layers

A few large trees can be seen in the developing layer; they can reach heights of 45–55 metres above the surrounding canopy. However they are more likely to grow to be 70–80 metres long. Over particular regions of the canopy, these trees must survive high temperatures and strong winds. This stratum is home to numerous unusual animal species, including the fox, king monkey, and crowned eagle.


The majority of tropical rainforests are found near and around the equator. Hence, there is such a thing as a tropical climate, which is defined by three primary climate factors: temperature, precipitation, and length of the dry seasons. Carbon dioxide concentrations, solar radiation, and nitrogen are additional factors that have an impact on tropical rainforests. These factors are all generally known.

Climatic patterns consist of high temperatures and the amount of annual precipitation. However, the large number of changes and rain throughout the year caused distinct wet and dry seasons.

A group of clouds controls the climate of these forests. These regions witnessed strong warming at a rate of 0.26 °C per decade, which coincides with the global rise in temperatures resulting from human inputs and the source of greenhouse gases in the atmosphere.

While rainforests are dwindling in number, ecotourism has grown in the tropics recently, and tourists are flocking to nations that still have these rich habitats.

Seeing animals, taking gorgeous jungle tours, and even visiting cultural landmarks and nearby towns are all part of ecotourism. If these procedures are followed correctly, they increase tourism-related economic support and enable higher revenues for habitat protection. The broad appreciation of the environment is enhanced by tourism.

Where are rainforests located?

Rainforests are found in the tropics, between the Tropic of Capricorn (the southern tropic) and the Tropic of Cancer (the northern tropic). The sun in this region is intense, shining daily in the same amount throughout the year. Therefore, the weather is warm and stable. In many countries, there are rainforests, and the countries that have large areas of rainforest are:

  1. Brazil
  2. Democratic Republic of the Congo
  3. Peru
  4. Indonesia
  5. Columbia
  6. Papua New Guinea
  7. Venezuela
  8. Bolivia
  9. Mexico
  10. Suriname

American rainforest

Rrubiaceae. Among the legumes are species from the genera Albizia, Lonchocarpus, and Anadinanthera, among others. In the Meliaceae, American cedar and mahogany are fine woody trees.

Species of the genus are of great importance in the family Moraceae, in addition to ficus and the ceiba Malvaceae. Rubiaceae are prominent underground with grasses and shrubs. In the Amazon, there are species of lecithidaceae called coco de mono and cap or artillery shell.

Cocoa is native to the Amazon basin, as is pineapple, a rosy herb of the bromeliad family.

African rainforest

Trees adapted to these conditions are found in the swampy forests of the Congo. Among others, they highlight Entandrophragma palustre, Citrulia under the violet, and Manilcara p. garcinia.

In the rainforests of West Africa, near the equator, there are species of fruit trees such as Dacryodes klaineana. Likewise, there are woody trees such as Strombosia glaucescens and medicinal ones such as Allanblakia floribunda. Kola nuts (sharp tail) used in producing soft drinks or cola soft drinks are native to this African bush. One of the most abundant plant families is the legume Bicolor Parkia, Parinari excelsa, and Piptadeniastrum africanum.

Asian rainforest

In the tropical swamp forests of Vietnam, species adapted to these conditions with rhizomes and pneumatophores have been found. Respiratory roots (pneumatophores) are anatomical structures specialised for ventilation.

Other species include Eugenia, Eleocarpaceae and Calophyllum. In the tropical rainforests of Thailand and Malaysia, teak is a tree with high-quality oil and wood. Another important wood species is Xylia dolabriformis, with very hard and valuable wood. In some forests, species of hardwood trees belonging to the Dipterocarpaceae family dominate.

Oceania rainforests

This area has warm rainforests with a canopy up to 30 meters high. Among the trees, there are species such as Rhus taitensis, Alphitonia zizyphoides and Casuarina equisetifolia. Lint ferns and shrubs of Macropiper puberulum and Psychotria insularum dominate the lower part. In Australia and New Zealand, there are forests where the dominant species is Eucalyptus.

Rainforest Plants

The family that characterises the popular image of the tropics is the Palmae or Arecaceae, and species of palms can be found in almost all tropical forests. Other families common among the tropical forests of America, Africa, Asia and Oceania are legumes, gutifrus, morasea and amias.

A defining feature of tropical rainforests worldwide, especially cloudy forests, is tree fern. These giant ferns are part of the forest and belong to the Cyatheaceae family.

Rainforest Animals

As we mentioned before, rainforests contain more than 50% of the living organisms on the planet, and they have several amazing animals and species that are charming to the eyes. They also feature a beautiful number of wonderful colours. Here are some of the animals in those forests.

  1. Mountain gorilla: is the largest primate (the highest order of mammals) on Earth, and it lives in groups of 30 individuals and one leader.
  2. Blue Morpho Butterfly: a tropical insect, shining in its blue colour as it flies over the tropical rainforest.
  3. Okapi: It is a tropical animal and the closest animal to the giraffe.
  4. Three-toed brown sloth: is a slow-moving animal, and algae grow on its back from its slowness. Its size is not large, weighing between eight and nine pounds.
  5. Jaguar: it is distinguished by the beautiful colours that help it hide among the trees, and this type preys on 85 types of prey.
  6. Water Pig: It is large, weighing 100 pounds, and reaching two feet in length, lives in dense vegetation surrounding the water, and hides from predators in the water.
  7. The scarlet parrot is one of the most beautiful and famous animals in the rainforest and is characterised by the colour of its bright red, blue and yellow feathers, and it has a strong beak that it can use to eat hard nuts.

There are abundant animals that populate the rainforest, and so many stories about these amazing forests that today they are being studied by many seasoned scientists.

You may also like to read about the Oldest Living Tree, Unique Tree Types, and Trees Facts.

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